What is the only way an engineer can alter the value of the bridge ID?

The value of the bridge ID in a network is critical for the functioning of the Spanning Tree Protocol (STP) as it determines which switch is considered the root bridge in a network topology. The bridge ID is comprised of two components: the bridge priority value and the MAC address of the switch.

Altering the STP priority directly changes the bridge ID because the priority is the first part of the bridge ID. If an engineer configures a switch with a new priority value, that modified priority will be combined with the switch's MAC address to form a new bridge ID. By lowering the priority value of a switch relative to others in the network, that switch can become the root bridge, thus altering the overall STP topology.

The other options provided do not affect the bridge ID in the same manner. Changing the VTP version relates to VLAN management rather than STP. Modifying the VLAN database involves managing VLAN configurations, not the bridge ID directly. Adjusting the trunk settings affects how VLAN information is propagated over trunk links but does not influence the bridge ID itself.